20633915018 has 4 divisors (see below), whose sum is σ = 30950872530. Its totient is φ = 10316957508.

The previous prime is 20633915017. The next prime is 20633915021. The reversal of 20633915018 is 81051933602.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81051933602 = 2 ⋅40525966801.

It can be written as a sum of positive squares in only one way, i.e., 19380259369 + 1253655649 = 139213^2 + 35407^2 .

It is not an unprimeable number, because it can be changed into a prime (20633915017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5158478753 + ... + 5158478756.

Almost surely, 2^20633915018 is an apocalyptic number.

20633915018 is a deficient number, since it is larger than the sum of its proper divisors (10316957512).

20633915018 is a wasteful number, since it uses less digits than its factorization.

20633915018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10316957511.

The product of its (nonzero) digits is 38880, while the sum is 38.

The spelling of 20633915018 in words is "twenty billion, six hundred thirty-three million, nine hundred fifteen thousand, eighteen".